«Yes. Who was the subject?»

«An old woman of sorts; died of pneumonia.»

«Yes. Turn back the pages of your drawing-book in your mind. What came before that?»

«Oh, some animals — still legs; I'm doing motor muscles at present. Yes. That was old Cunningham's demonstration on comparative anatomy. I did rather a good thing of a hare's legs and a frog's, and rudimentary legs on a snake.»

«Yes. Which day does Mr. Cunningham lecture?»

«Friday.»

«Friday; yes. Turn back again. What comes before that?»

Mr. Piggott shook his head.

«Do your drawings of legs begin on the right-hand page or the left-hand page? Can you see the first drawing?»

«Yes — yes — I can see the date written at the top. It's a section of a frog's hind leg, on the right-hand page.»